RE: Pattern synonym constraints :: Ord a => () => ...

ytonjo...@gmail.com<mailto:simon.peytonjo...@gmail.com> instead. (For now, it just forwards to simo...@microsoft.com.) From: Anthony Clayden Sent: 06 October 2021 11:42 To: Simon Peyton Jones Cc: Gergő Érdi ; GHC users Subject: Re: Pattern synonym constraints :: Ord a => () => ...

RE: Pattern synonym constraints :: Ord a => () => ...

Perhaps I'm just stupid, and should be disqualified from using such features. Only as a result of this thread (not from the User Guide nor from the paper) do I discover "use" means match-on. You are not stupid. And since you misunderstood despite effort, the presentation is - by definition -

RE: -dinline-check for symbolic names?

: Michael Sperber | Sent: 18 August 2021 14:14 | To: Simon Peyton Jones | Cc: glasgow-haskell-users@haskell.org | Subject: Re: -dinline-check for symbolic names? | | | On Tue, Aug 10 2021, Simon Peyton Jones wrote: | | > It's hard to tell what is happening without a repro case. Can

RE: Avoiding construction of dead dictionaries

? Not sure what you mean here, but once we have a repro case we can discuss. Worth opening a ticket too -- email is easily lost. Thanks Simon | -Original Message- | From: Michael Sperber | Sent: 12 August 2021 10:15 | To: Simon Peyton Jones | Cc: Sebastian Graf ; glasgow-haske

RE: InstanceSigs -- rationale for the "must be more polymorphic than"

August 2021 12:01 To: Simon Peyton Jones Cc: Anthony Clayden ; GHC users Subject: Re: InstanceSigs -- rationale for the "must be more polymorphic than" Simon, there are times when a function has to be generalized to be made polymorphic recursive. Perhaps the method takes an argument

RE: -dinline-check for symbolic names?

It's hard to tell what is happening without a repro case. Can you share one? You suggested that it might have something to do with using an operator. Does the same thing happen if you replace the operator with an alpha-numeric name? Simon | -Original Message- | From:

RE: InstanceSigs -- rationale for the "must be more polymorphic than"

AntC, I think you see why the instance sig must be at least as polymorphic than the instantiated signature from the class - because that's what the client is going to expect. We are building a record of functions, and they must conform to the class signature. I agree with David's (1) and (2)

RE: Avoiding construction of dead dictionaries

Hi Mike | The right-hand argument of <+ leads to a dictionary construction that is a | proof of a certain property, but the dictionary itself ends up being dead, | like so: | |case $w$dOpCon_r2kGJ ... |of |{ (# ww1_s27L3 #) -> ... } | ^ |

RE: Avoiding construction of dead dictionaries

> . So apparently it is possible for a dictionary to be bottom somehow. That should not happen. Except in the case of single-method dictionaries like class C a where op :: a -> a In these cases the "dictionary" is represented by a newtype, like this newtype C a =

[Haskell] Nominations close Jan 11th for the Haskell Foundation Board

strong Board, and that means strong nominations. Thanks! Please do forward this message on social media or elsewhere. Simon Peyton Jones ___ Haskell mailing list Haskell@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell

RE: exhausted simplifier ticks and hs-boot files

Ganesh It's an old bug that has somehow reappeared. I opened https://gitlab.haskell.org/ghc/ghc/issues/17140 But it seems OK in HEAD, and hence probably in GHC 8.8. Can you try? Maybe put further comments on the issue tracker, rather than here. thanks Simon | -Original Message- |

RE: Equality constraints (~): type-theory behind them

I'd far rather see GHC's implementation of FunDeps made more coherent (and learning from Hugs) than squeezing it into the straitjacket of System FC and thereby lose expressivity. To call System FC a straitjacket is to suggest that there is a straightforward alternative that would serve the

[Haskell] Guidelines for respectful communication

Friends As many of you will know, I have been concerned for several years about the standards of discourse in the Haskell community. I think things have improved since the period that drove me to write my Respect email,

Guidelines for respectful communication

Friends As many of you will know, I have been concerned for several years about the standards of discourse in the Haskell community. I think things have improved since the period that drove me to write my Respect email,

[Haskell] Summit on Advances in Programming Languages 2019

Haskellers The Summit oN Advances in Programming Languages (SNAPL) is a biennial venue for discussions about programming languages. SNAPL focuses on experience-based insight, innovation, and visionary ideas spanning from foundations to applications of

Summit on Advances in Programming Languages 2019

Haskellers The Summit oN Advances in Programming Languages (SNAPL) is a biennial venue for discussions about programming languages. SNAPL focuses on experience-based insight, innovation, and visionary ideas spanning from foundations to applications of

Re: [Haskell-community] 2018 state of Haskell survey results

Just wanted to add in: good catch Gershom on identifying the problem, and thank you Taylor for working to remove them from the report. I'd like to add +1 to that. It's a source of astonishment, and some dismay, to me that anyone would go to so much trouble to affect a survey about Haskell.

RE: A question about run-time errors when class members are undefined

Anthony You may be interested in Carlos Camarao’s interesting work. For a long time now he has advocated (in effect) making each function into its own type class, rather that grouping them into classes. Perhaps that is in line with your thinking. https://homepages.dcc.ufmg.br/~camarao/

Re: [Haskell-community] Creating a new @haskell.org mailing list?

Good idea. “k12” is rather USA specific. What about educat...@haskell.org? Simon From: Haskell-community On Behalf Of Chris Smith Sent: 22 October 2018 15:32 To: Haskell-community Subject: [Haskell-community] Creating a new @haskell.org mailing list? Hey, Is

[Haskell] Postdoc and internship opportunities at Microsoft Research Cambridge

18. Informal enquiries to Andy Gordon a...@microsoft.com or Simon Peyton Jones simo...@microsoft.com ___ Haskell mailing list Haskell@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell

Re: [Haskell-community] 2018 state of Haskell survey

| Hi Taylor. I like the way you pose things here: "I don't expect that | to remove selection bias, but it will let me (us, really) say: We're | doing this together for the benefit of all sides". I think that's a | better place to start from. I like this too -- and like Gershom, I'd delete

Re: [Haskell-community] 2018 state of Haskell survey

or excluded in our shared enterprise of making GHC a better tool. Simon | -Original Message- | From: Taylor Fausak | Sent: 16 October 2018 00:43 | To: Simon Peyton Jones ; Gershom B | ; Mathieu Boespflug ; Ben Gamari | | Cc: haskell-community@haskell.org | Subject: Re: [Haskell-community

Re: [Haskell] Treatment of unknown pragmas

I rather agree. We don't even need a convention do we? /Any/ comment in {- -} is ignored by GHC /except/ {-# ... #-}. So tool users are free to pick whatever convention they like to identify the stuff for their tool. Simon | -Original Message- | From: ghc-devs On Behalf Of Ben Gamari

Re: [Haskell-community] 2018 state of Haskell survey

The GHC team (coincidentally) is cooking up a very short survey that is intended to help guide our strategic priorities. There is only one substantial question: Imagine that you had one developer working on GHC for six months full-time, that you were paying for yourself.

RE: Quo vadis?

October 2018 02:52 | To: Simon Peyton Jones ; haskell-prime@haskell.org | Subject: Re: Quo vadis? | | On 2018-10-05 01:05 PM, Simon Peyton Jones wrote: | > I think the difficulty has always been in finding enough people who | > are | > | > * Well-informed and well-qualified |

RE: Quo vadis?

I think the difficulty has always been in finding enough people who are * Well-informed and well-qualified * Willing to spend the time to standardise language features GHC does not help the situation: it's a de-facto standard, which reduces the incentives to spend time in standardisation. I

RE: Natural number comparisons with evidence

I see this in GHC.TypeNats sameNat :: (KnownNat a, KnownNat b) => Proxy a -> Proxy b -> Maybe (a :~: b) sameNat x y | natVal x == natVal y = Just (unsafeCoerce Refl) | otherwise= Nothing The unsafeCoerce says that sameNat is part of the trusted code base. And

RE: Open up the issues tracker on ghc-proposals

I can volunteer to at least scrape together all the objections to ScopedTypeVariables as currently. It's not yet a proposal, so not on github. Start a wiki page? A cafe thread? (It'll get lost.) A ghc-users thread? (It'll get ignored.) That’s a fair question. We have lots of forums, but your

RE: Open up the issues tracker on ghc-proposals

| > Sometimes, a language extension idea could benefit from | some community discussion before it's ready for a formal proposal. | | Can I point out it's not only ghc developers who make proposals. I'd | rather you post this idea more widely. The Right Thing is surely for the main GHC

Haskell Report 2010: pattern bindings

ch does not handle top-level bindings. I’m not sure if this is worth fixing. Simon From: José Manuel Calderón Trilla <j...@jmct.cc> Sent: 15 March 2018 23:17 To: Simon Peyton Jones <simo...@microsoft.com>; haskell-prime@haskell.org; ghc-d...@haskell.org Subject: Re: [Haskell] The

The Haskell Report: who maintains it?

Friends Does anyone know who, if anyone, feels responsible for committing updates to the Haskell 2010 Report? Who even has commit rights? There’s Frank’s pull request below, and I have another important typo to fix. Thanks Simon From: Frank Steffahn [mailto:notificati...@github.com] Sent:

[Haskell] The Haskell Report: who maintains it?

Friends Does anyone know who, if anyone, feels responsible for committing updates to the Haskell 2010 Report? Who even has commit rights? There’s Frank’s pull request below, and I have another important typo to fix. Thanks Simon From: Frank Steffahn [mailto:notificati...@github.com] Sent:

RE: How to highlighting subexpressions in dumped core?

I'm not keen on adding more Tick complexity -- it's a bit out of hand already, and all transformations must "do the right thing". AnnExpr adds an annotation at every node. You could, I guess use that to annotate -- but then you'd need a pretty printer for it so you'd end up with duplication.

[Haskell] SLURP: a single unified registry for Haskell packages

b.com/boes>) Manuel Chakravarty (@mchakravarty<https://github.com/mchakravarty>) Simon Marlow (@simonmar<https://github.com/simonmar>) Simon Peyton Jones (@simonpj<https://github.com/simonpj>) Alan Zimmerman (@alanz<https://github.com/alanz>) __

RE: Why is EvTerm limited?

| What would break if we had | | | EvExpr CoreExpr | | as an additional constructor there? This has come up before. I think that'd be a solid win. In fact, eliminate all the existing evidence constructors with "smart constructors" that produce an EvExpr. That'd mean moving stuff from

Re: [Haskell] A small milestone

C01%7Csimonpj%40microsoft.com%7Cc4d7a883633f4bc5be7308d55e975753%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636518926451639509=PIKf6Tp95N2w%2F%2BwnQwyLNkuoIP5p%2F%2FofI%2B7eAccJnJM%3D=0> . Simon From: Haskell-Cafe [mailto:haskell-cafe-boun...@haskell.org] On Behalf Of Simon Peyton Jones via H

[Haskell] A small milestone

Cherished friends Today is my sixtieth birthday. It is just over forty years since Phil and I called in at Yale on my way to FPCA, and floated the idea of Haskell with Paul Hudak. (It wasn't

RE: GHC rewrite rule type-checking failure

* Is it feasible for GHC to combine the constraints needed LHS and RHS to form an applicability condition? I don’t think so. Remember that a rewrite rule literally rewrites LHS to RHS. It does not conjure up any new dictionaries out of thin air. In your example, (D k b) is needed in the

RE: Inhibiting the specialiser?

Did you try -fno-specialise? From: Glasgow-haskell-users [mailto:glasgow-haskell-users-boun...@haskell.org] On Behalf Of Conal Elliott Sent: 15 September 2017 02:45 To: glasgow-haskell-users@haskell.org Subject: Inhibiting the specialiser? Is there a GHC flag for inhibiting the specializer (but

RE: Remove eq and show from num class

Good summary Herbert. It'd be great to have it as a page on haskell.org, rather than just in soon-lost email. Simon | -Original Message- | From: Haskell-prime [mailto:haskell-prime-boun...@haskell.org] On Behalf | Of Herbert Valerio Riedel | Sent: 08 September 2017 09:43 | To: Anthony

RE: Trouble with injective type families

Functional dependencies and type-family dependencies only induce extra "improvement" constraints, not evidence. For example class C a b | a -> b where foo :: a -> b instance C Bool Int where ... f :: C Bool b => b -> Int f x = x -- Rejected Does the fundep on

RE: 8.2.1-rc2 upgrade report

Thanks for the report. Going from 67G to 56G allocation is a very worthwhile improvement in runtime! Hurrah. However, trebling compile time is very bad. It is (I think) far from typical: generally 8.2 is faster at compiling than 8.0 so you must be hitting something weird. Anything you can

RE: Unused import warning on re-export

| Is there a reason GHC considers this case an unused import? It seems that | the use of the import is explicitly stated right within the import | itself. Should I submit a ticket for this? Hmm. I think you are saying that module A where import B as A(f) g = True that is equivalent

RE: join points and stream fusion?

Thank you! | -Original Message- | From: Christian Höner zu Siederdissen [mailto:choe...@bioinf.uni- | leipzig.de] | Sent: 28 April 2017 00:14 | To: Simon Peyton Jones <simo...@microsoft.com> | Cc: glasgow-haskell-users@haskell.org | Subject: Re: join points and stream

RE: join points and stream fusion?

I'm afraid I don't have enough context to understand this thread. Could you offer a concrete example (as small as possible), and explain how to reproduce the problem you are seeing. Don't forget to give the compiler version you are using, and any libraries you depend on (as few as poss). Is

RE: Why isn't this Overlapping?

Moreover, as discussed in the user manual section, GHC doesn’t complain about overlapping instances at the instance decl, but rather where the instances are used. That’s why there is no overlap

RE: Accessing the "original" names via GHC API

The TyCon has a Name (use tyConName to get it). The Name has a Module and an OccName (use nameModule and nameOccName to get them) The OccName has a string (occNameString) The Module has a ModuleName and a Package. All of these will give the “original-name” info, ignoring what’s in scope. Does

RE: GHC rewrite rules for class operations & laws

[mailto:b...@smart-cactus.org] | Sent: 29 December 2016 14:50 | To: Conal Elliott <co...@conal.net>; George Colpitts | <george.colpi...@gmail.com> | Cc: glasgow-haskell-users@haskell.org; Simon Peyton Jones | <simo...@microsoft.com> | Subject: Re: GHC rewrite rules for class

RE: GHC rewrite rules for class operations & laws

Conal Is it possible to apply GHC rewrite rules to class methods? Not currently. See https://ghc.haskell.org/trac/ghc/ticket/11688, esp comment:7 which gives links to similar examples. https://ghc.haskell.org/trac/ghc/ticket/10528 comment:13 gives more background. It’d be great if someone

RE: Getting rid of -XImpredicativeTypes

a swamp. I have tried multiple times to fix ImpredicativeTypes, and failed every time. Which is not to say that someone shouldn’t try again, with new thinking. Simon From: Dan Doel [mailto:dan.d...@gmail.com] Sent: 26 September 2016 00:54 To: Simon Peyton Jones <simo...@microsoft.com> Cc:

FW: Getting rid of -XImpredicativeTypes

Friends GHC has a flag -XImpredicativeTypes that makes a half-hearted attempt to support impredicative polymorphism. But it is vestigial…. if it works, it’s really a fluke. We don’t really have a systematic story here at all. I propose, therefore, to remove it entirely. That is, if you use

[Haskell] Respect

Friends One of the most precious attributes of the Haskell community over the last twenty-five years has been its supportive, friendly, and respectful dialogue. People have often drawn attention to this, and I have always felt good about it.  (A great example is this hilarious exchange [1],

RE: Type families in kind signatures with TypeInType

19:51 To: Simon Peyton Jones <simo...@microsoft.com> Cc: glasgow-haskell-users@haskell.org Mailing List <Glasgow-haskell-users@haskell.org> Subject: Re: Type families in kind signatures with TypeInType On Fri, Sep 23, 2016 at 3:19 AM, Simon Peyton Jones <simo...@microsoft.com<mail

RE: Type families in kind signatures with TypeInType

This is an example of https://ghc.haskell.org/trac/ghc/ticket/12088. The “type instance T List” declaration actually depends on the “type instance K List” declaration; the latter must be typechecked before the former. But this dependency is absolutely unclear. There’s a long discussion on the

RE: GHC Performance / Replacement for R?

Sounds bad. But it'll need someone with bytestring expertise to debug. Maybe there's a GHC problem underlying; or maybe it's shortcoming of bytestring. Simon | -Original Message- | From: Glasgow-haskell-users [mailto:glasgow-haskell-users- | boun...@haskell.org] On Behalf Of

RE: ArgumentDo proposal updated

I've added record construction and update to the syntax, which makes it clearer how the other constructs are analogous to them. Simon | -Original Message- | From: Glasgow-haskell-users [mailto:glasgow-haskell-users- | boun...@haskell.org] On Behalf Of Akio Takano | Sent: 11 July

RE: Rethinking GHC's approach to managing proposals

Just to be clear: * We are actively seeking feedback about the proposal [4] below. It's not a fait-accompli. * You can join the dialogue by (a) replying to this email, (b) via the "Conversations" tab of [4], namely https://github.com/ghc-proposals/ghc-proposals/pull/1 Doubtless via

Simon's email classified as spam

(but perhaps not everyone else)? Thanks Simon | From: Gershom B [mailto:gersh...@gmail.com] | Sent: 18 June 2016 18:53 | To: Simon Peyton Jones <simo...@microsoft.com>; John Wiegley | <jo...@newartisans.com> | Cc: Michael Burge <michaelbu...@pobox.com> | Subject: Re: FW: CM

RE: CMM-to-ASM: Register allocation wierdness

, could you let me know? Thanks Simon From: Takenobu Tani [mailto:takenobu...@gmail.com] Sent: 18 June 2016 08:18 To: Simon Peyton Jones <simo...@microsoft.com> Subject: Re: CMM-to-ASM: Register allocation wierdness Hi Simon, I report to you about your mails. Maybe, your mails don't reach to

RE: CMM-to-ASM: Register allocation wierdness

| All-in-all, the graph coloring allocator is in great need of some love; | Harendra, perhaps you'd like to have a try at dusting it off and perhaps | look into why it regresses in compiler performance? It would be great if | we could use it by default. I second this. Volunteers are sorely

RE: Pattern synonyms and GADTs in GHC 8.0.1

GHC 8.0 swaps the order of provided vs required contexts in a pattern synonym signature. (7.10 was advertised as experimental). Thus: pattern AddP :: () => (Num a, Eq a) => Exp a -> Exp a -> Exp a Then it's fine Simon | -Original Message- | From: Glasgow-haskell-users

RE: suboptimal ghc code generation in IO vs equivalent pure code case

As Harendra has found, the biggest difference is probably that the IO version is necessarily strict, constructing the entire list (via the stack) before it returns, whereas the pure one is lazy, constructing the list only on demand. So the memory footprint of the lazy one will be asymptotically

RE: Are there GHC extensions we'd like to incorporate wholesale?

Just to be clear, MonoLocalBinds, as implemented, does not apply to local bindings that could equally well have been written at top level; that is, they do not mention any locally-bound variables (except other local bindings that could themselves be floated). So you are at liberty to use where

RE: Looking for GHC compile-time performance tests

Thanks. A repeatable test case would be incredibly helpful here. Simon | -Original Message- | From: Glasgow-haskell-users [mailto:glasgow-haskell-users- | boun...@haskell.org] On Behalf Of Edward Kmett | Sent: 05 May 2016 21:50 | To: Erik de Castro Lopo | Cc:

RE: Are there GHC extensions we'd like to incorporate wholesale?

| For example, much as I love GADTs and would be all for them being added | in some future language report, I do not feel they should be added this | time around. (Though I emphatically and wholeheartedly support adding | GADTSyntax.) The primary reason being that while the semantics of the |

RE: Chairship / responsibility

| It was my understanding that Herbert would be the chair when I asked to | be on the committee, and the fact that this question was already answer | was a factor in my decision to try to help. Being the committee chair | is less a position of power, and more a position of responsibility. I |

RE: Magic classes for Overloaded Record Fields, overlaps, FunDeps

| > I have been vacillating between type families and fundeps for the ORF | > classes. I hadn't fully appreciated this point about overlap, but I | > think it is a reason to prefer fundeps, which is the direction in | > which I'm leaning. I'd be grateful for feedback on this issue though! ...

RE: Were usage types ever in GHC

Keith Wansbrough did implement his thesis work in a fork of GHC. But (a) it was jolly complicated and pervasive, and (b) the performance improvements were not great. It didn't pay its way. So we dropped it. See his thesis, available here

RE: suppress warning "Defined but not used: type variable ‘x’" in GHC-8.0

I have created not one but three tickets arising from this thread: · https://ghc.haskell.org/trac/ghc/ticket/11449 · https://ghc.haskell.org/trac/ghc/ticket/11450 · https://ghc.haskell.org/trac/ghc/ticket/11451 I’d love comments on them: which of the three matter most

RE: Warnings, -Wall, and versioning policy

Thanks Gershom. That all sounds fine to me. An implication is that GHC is free to introduce new warnings X into -Wall. Indeed doing so would be good, because the warning X might later move into the default set. Indeed for such warnings, adding a "PS: this warning will become the default

RE: Warnings, -Wall, and versioning policy

OK. When this thread comes to a conclusion, can someone write it down; update the 3-release policy; and say what changes you want in GHC? Thanks Simon | -Original Message- | From: Gershom B [mailto:gersh...@gmail.com] | Sent: 13 January 2016 18:18 | To: Simon Peyton Jones <s

RE: type error formatting

I’m all for it. Can advise. (Make a ticket.) Thanks! Simon From: Glasgow-haskell-users [mailto:glasgow-haskell-users-boun...@haskell.org] On Behalf Of Evan Laforge Sent: 24 October 2015 03:48 To: GHC users Subject: type error formatting Here's a typical simple type error from GHC:

RE: Breaking Changes and Long Term Support Haskell

| > Are these three technical capabilities *all* that we would need? | > Perhaps | > we also need a way to tie the current language (-XHaskell98, | > -XHaskell2010) to a particular implementation of the Prelude. | > | > | > I don't have a concrete plan here. I'm not even sure one

RE: Breaking Changes and Long Term Support Haskell

| Cc: Simon Peyton Jones; Augustsson, Lennart; Henrik Nilsson; haskell- | pr...@haskell.org List; Haskell Libraries | Subject: Re: Breaking Changes and Long Term Support Haskell | | Hello, | | I'm Dan Doel. I'm on the core libraries committee (though I'm speaking | only for myself). As I recall, one

RE: Breaking Changes and Long Term Support Haskell

| For the record, I am also not sure Proposal 3 is a good idea :) | | However, I do think we could clarify what the respective | responsibilities of the core libraries committee and Haskell Prime | committees are. My instinct is this: Haskell Prime: language Core Libraries Committee:

RE: Breaking Changes and Long Term Support Haskell

Friends I think it's good for us to debate the question of how we should balance innovation against change; and how we should make those decisions in future. Geoff's message had some good ideas, especially this bit: | Proposal 2: After a suitable period of discussion on the libraries list,

RE: [Haskell-cafe] MRP, 3-year-support-window, and the non-requirement of CPP (was: Monad of no `return` Proposal (MRP): Moving `return` out of `Monad`)

I think there are several different conversations going on at once in this thread. I think it’s worth keeping them separate. · Haskell Prime. The intention there is to take a set of language features that are already in wide use in GHC (i.e. have demonstrably proved valuable), work

Re: [Haskell] [Haskell-cafe] ANN: Creation of Haskell-Community list for Haskell.org Community Infrastructure Discussions

| But this leaves open people wondering what those discussions are. And | it also leaves open where the *designated place* to discuss | haskell.org community infrastructure is. The haskell-infrastructure | [2] list is very quiet and really about technical considerations. | Meanwhile, -cafe,

RE: tweaking text on the ghc downloads page

I’m ok with all of this, but I’d like just to check with Mark L to see how he suggests signposting the HP Simon From: Glasgow-haskell-users [mailto:glasgow-haskell-users-boun...@haskell.org] On Behalf Of Michael Snoyman Sent: 26 June 2015 15:59 To: Gershom B; Glasgow-Haskell-Users users

RE: overlapping instances in 7.10.1

Sergei I finally found time to look into what is happening here. It's a good illustration of the dangers of overlapping instances. Here is the setup: * Module ResEuc_ * Contains instance (...)= Ring (ResidueE a) (A) instance (..., Ring

7.10 branch

Austin I'm getting these validation failures on the 7.10 branch. Are you? This is on Linux. Simon Unexpected failures: driverT8959a [bad stderr] (normal) ghci/scripts T9878b [bad stderr] (ghci) thT10279 [stderr mismatch] (normal) Unexpected stat failures:

RE: Closed Type Families: separate instance groups?

I think it's pretty good as-is. * Use an open family (with non-overlapping instances) to get yourself into part of the match space: type instance OpenF (Foo b c) = FFoo (Foo b c) * Use a closed family (with overlap and top-to-bottom matching) to deal with that part of the space:

RE: Increased memory usage with GHC 7.10.1

It would be great if someone could · create a ticket for Paolio · investigate what is happening This smaller test case uses Repa, so it’s not clear that GHC is doing anything wrong. Maybe repa is inlining too much? We need insight. Thanks SImon From: Glasgow-haskell-users

RE: Increased memory usage with GHC 7.10.1

Can you open a ticket, please? And put as much data as you can. Using `-dshow-passes` (both for 7.10 and prior versions) and showing the output would be helpful. Simon From: Glasgow-haskell-users [mailto:glasgow-haskell-users-boun...@haskell.org] On Behalf Of Paolino Sent: 01 May 2015 09:42

RE: SIMD

Geoff Mainland is the originator of the SIMD instruction set work. Let’s see what he says. Simon From: Glasgow-haskell-users [mailto:glasgow-haskell-users-boun...@haskell.org] On Behalf Of Dominic Steinitz Sent: 11 April 2015 17:45 To: GHC users Subject: SIMD What’s the story with this? I

RE: Typed splices and type checking

Good question! See https://ghc.haskell.org/trac/ghc/ticket/10271. Simon | -Original Message- | From: Glasgow-haskell-users [mailto:glasgow-haskell-users- | boun...@haskell.org] On Behalf Of J. Garrett Morris | Sent: 27 March 2015 14:30 | To: GHC users | Subject: Typed splices and type

RE: Binary bloat in 7.10

Just to check, can someone summarise the conclusion of this thread? Was it all due to -fsplit-objs? If so, should we add some notes to the user manual to explain what may happen if you use -fsplit-objs? What was the business about Cabal? Simon | -Original Message- | From:

RE: Splices returning splices

Currently it just isn't supported. Suppose you say f x = [| $(g y) |] ...$(f 3) Does $(f 3) mean run (f 3) returning some code with embedded splices, and then run those, or does it mean (as now) call (f 3), and to do so run (g y) first, to generate some code that is spliced into

RE: Qualified names in TH?

What Edward says also applies to code quotations. So, for example: module M import IntSet f :: Q Exp - Q Exp f blah = [| fromList $blah |] module N where import M h x = $(f [| [x,x] |]) The splice expands to (fromList [x,x]), but the fromList guaranteed to be the fromList

[Haskell] GHC 7.10 will use Plan FTP

Marlow and Simon Peyton Jones ___ Haskell mailing list Haskell@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell

Re: [Haskell] Rank-N types with (.) composition

($) has its own *typing rule*; it does not have a special type. It's very ad hoc, but ($) is used so much to decrease parens that (e1 $ e2) is almost special syntax! At the moment the *only* robust way to pass a polymorphic function to a polymorphic function (here, you are passing Wrap to

Re: [Haskell] [Haskell-cafe] GHC 7.10 Prelude: we need your opinion

for. (Which I failed to send the announcement to! I'll fix that.) Simon | -Original Message- | From: Miguel Mitrofanov [mailto:miguelim...@yandex.ru] | Sent: 10 February 2015 15:59 | To: Simon Peyton Jones; haskell@haskell.org; Haskell Cafe (haskell- | c...@haskell.org); GHC users

GHC 7.10 Prelude: we need your opinion

, libraries, etc etc), so we want to ask your opinion rather than guess it. · Ask Simon Marlow and Simon Peyton Jones to decide which approach to follow for GHC 7.10. Wiki pages have been created summarizing these two primary alternatives, including many more points and counter-points

RE: [Haskell-cafe] GHC 7.10 Prelude: we need your opinion

for. (Which I failed to send the announcement to! I'll fix that.) Simon | -Original Message- | From: Miguel Mitrofanov [mailto:miguelim...@yandex.ru] | Sent: 10 February 2015 15:59 | To: Simon Peyton Jones; hask...@haskell.org; Haskell Cafe (haskell- | c...@haskell.org); GHC users

[Haskell] GHC 7.10 Prelude: we need your opinion

, libraries, etc etc), so we want to ask your opinion rather than guess it. · Ask Simon Marlow and Simon Peyton Jones to decide which approach to follow for GHC 7.10. Wiki pages have been created summarizing these two primary alternatives, including many more points and counter-points

RE: Proposal: ValidateMonoLiterals - Initial bikeshed discussion

I'm all for it. Syntax sounds like the main difficulty. Today you could use quasiquotatoin [even| 38 |] and get the same effect as $$(validate 38). But it's still noisy. So: what is the non-noisy scheme you want to propose? You don't quite get to that in the wiki page! Simon |

Re: [Haskell] Haskell Weekly News: Issue 316

After doing more than 150 of these, I have come to the conclusion that it is time for me to take a permanent break from HWN. I realize that we could do better, and have something a bit more edited than a collection of links, and some quotes. I wish I had more time to devote to such endeavour,

RE: Restricted Template Haskell

). For the latter there is already a page herehttps://wiki.haskell.org/Template_Haskell. I’d really appreciate help with this. Simon From: Greg Weber [mailto:g...@gregweber.info] Sent: 03 February 2015 03:42 To: Simon Peyton Jones Cc: ghc-d...@haskell.org; GHC users; David Terei; Maxwell Swadling Subject: Re

RE: stream fusion, concatMap, exisential seed unboxing

I think it'd help you to open a Trac ticket, give a fully-reproducible test case, including instructions for how to reproduce, and say what isn't happening that should happen. What's odd is that loop_s29q looks strict in its Int arg, yet isn't unboxed. There is a way to get the strictness

RE: Restricted Template Haskell

The new TH is already split into two partshttps://ghc.haskell.org/trac/ghc/blog/Template%20Haskell%20Proposal as I’m sure you know · Typed TH is for expressions only, and doesn’t have reify, nor any Q monad. · Untyped TH is the wild west Typed TH may get some of what you

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